Should I use a drying aid when drying my car?

A drying aid adds lubrication between the towel and the paint, which reduces the risk of fine scratches, and some leave a light protective layer. It is not essential on a slick, well-protected surface, but it is helpful on bare paint or in hard-water areas. Choose a product compatible with any coating on the car, use only a light mist and avoid hot panels, where drying aids can streak.